The Secret at Shadow Ranch, published in 1931, was the fifth in the acclaimed line of Nancy Drew mysteries. Publishers Weekly has ranked it as the fiftieth best-selling children's book of all time, with over 2.3 million in sales.

In this book, Nancy is invited with three friends to spend the summer in the American West. They are accompanying Mrs. Rawley, whose husband has acquired Shadow Ranch, a rundown property, which she has to restore and sell.

The four girls settle comfortably into the ranch and learn to ride well enough to explore the beautiful but rugged countryside. They face down harsh rainstorms, floods, and menacing wild animals.

During their explorations, the girls come across a rundown shack inhabited by the eccentric and cantankerous Martha Frank, who shelters a beautiful but neglected child named Lucy Brown. Martha abuses Lucy and does not allow her to talk to anyone.

Nancy, concerned for Lucy's well-being, looks into this enigma. She is drawn into confrontation with Martha and with Zany Shaw, a cranky junk dealer, who is somehow connected with Martha.

While unraveling this mystery, Nancy befriends Ross Rogers, a befuddled bookseller who proves to be an integral part of the story.

The Nancy Drew mysteries debuted in a fast-changing America, where women were discarding traditional roles and asserting themselves. Nancy models this new American woman: strong-willed, intelligent, indomitable, as well as educated and sophisticated.

In the nearly 100 years since their premiere, the Nancy Drew mysteries have become an integral part of the American feminine mythos.

The Secret at Shadow Ranch, like the others in the series, is attributed to the pseudonymous Carolyn Keene. In fact Nancy was the creation of publisher Edward Stratemeyer, who engaged a number of ghostwriters to develop the books. Mildred Wirt Benson is credited with writing The Secret at Shadow Ranch.

The evergreen popularity of the Nancy Drew series led to many film and television adaptations. Today, nearly 100 years after their launch, the Nancy Drew books remain classics of young adult fiction.